Furnace for heating or annealing.



A A. SMALLIWQOD. FUiHNACE FOR HEAlNG 0R ANNEALING.

APPLICATION FILED SEPIT. 2l 1914.

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A. SMALLWOOD. FURNACE FOR HEATING 0R ANNEALING.

APPLICATION FILED SEPT-ZI; IQIII. ygo Patented May 15, IIN?.

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. llallftEl) SMALLWOOD, OF LONDON, ENGLAND, ASSIGNOR TO AMERICAN IN CANDESCENT HEAT COMPANY, F PORTLAND, MAINE, A CORPORATION 0F MAINE.

Tall whom t may concern Be it known that I, ALFREDSMALLWOOD,

vsiding at .42 Hargrave Park, l-Iighgate, Lonsv don, N., in the county of Middlesex, Enga land, have invented Improvements in or Rei .v lating to Furnaces for Heating or Annealing, of 4w-hich the following is a' specification.

In the construction ous purposes it has, almost uniformly, been the aim of designers to prevent complete combustion, for, if the substance being heated (and a notable example is found in the case of steam boilers) is below the flash point of the burning gases, such gases as come vthe relatively cool substance will notbe ignited.- Accordingl in the patents which vhave heretoforebeen issued tome, I have lshown various arrangements of furnaces in which combustion can be more or less completed before the'gases are brought in contact with substances at a temperature below their flash point.

vmy present invention, the amount of heat available'for use at any'given time is very llargely dependent on thelamount of fuel being consumed. F or example, if a charge of co d metal Iis put into such a furnace, which has been brought to a working temperature, the metal will at onceabsorb all the available heat and cool down the furnace, which must wait until newheat is generated before yits temperature can reach the point necesl sary for the desired treatment.

By my present invention I am able to manufacture furnaces for a great variety of uses', in which the heat is poured steadily into a reservoir where it may be stored up ready for use and from which it may be drawn at any time or to any point desired. By accompllshing -this storage of heat I have onhand, at. all times, a reserve that kmay be utilized to meet extraordinary del' mands, whereby I am able to maintain the heat at an extraordinarily even level. This not only'enablesme to produce results far superior to those heretofore accomplished,

but further,`the fact that the heat can be poured uniformly into vthe. reservoirv greatly l Specification of Letters Patent.

-of labor necessary can be decreased, for, when deslred, from a of,y furnaces for Avarito cause combustion to. take place at the point where the heat is to y be utilized. Such procedure tends, however, y i 15 within the viniiuence of` In these furnaces, howi 4- ever, as 1n all furnaces known to me before rui-'amen ron HEATING oaaulvnatnre.

Patented May i5, reir.

j Application filed September 21, 1914:. Serial No. 862,753. v

decreases the amount of fuel that need be consumed. At the same time the amount tov operate the furnaces single heat reservoir, supplied by a single fire grate, heat may be "drawn for use in a large number of independent furnaces, that may be used for different purposes and operated at different temperatures.

Broadly speaking, my invention consists in supplying the furnace with -a grate or other place for initial combustion, preferably litted with means for controlling the ,supply of air; a heat reservoir of sufficient volume so that the combustion of the generlated gases may be completed within it and which may be supplied with a separate supply of air to vassist if an oxidizbe supplied with such additionalQ-airifit is desired to take .advantage voffthe large combustion free oxygen present to combine with carbon and. th'us produce a non-oxidizing atmosphere in the working chamber, together; with controllable means for distributing the heat from the reservoir to various points in the working chamber.

In practice, the distribution of heat is usually accomplished by splitting up the reservoir space into a main chamber wellv Y rated from the workinq chamber by a parti tion through which the heat will radiate, lgiving a large amount of evenly distributed eat, in addition to that which may be transmitted directly to the working chamber through properly positioned and controlled ports. y

By inclosing the main heat chamber in walls through which relatively little heat can penetrate to the exterior of the furnace, and. by using with the working chamber aI separate radiating chamber Vhaving controllable ports, great storage efiiciency can be attained, for it is apparent that if the ports leading from the radiating chamber to the corresponding working' chamber are closed, no gases will pass into the radiating chamchamber to cause substantially all of the ber, and the amount of heat that will penetrate into the radiating chamber and throu h to the Working chamberwill be very sma In the same way, if the working chamber. 1s

5 to be maintained at a temperature already reached, only a small amount of heat need be drawn from the main heat chamberto replenish that being taken from the radiating chamber, so the ports are kept open only a very little way. On the other hand, 1f a great amount of heat 1s neededat once, as when .-a new charge of materlals 1s belng treated, the furnace must beso built that a reat amount of heat can be instantly drawn rom the radiating `chamber Whichtin turn, must be kept supplied from the `mam reservoir. "To accomplish this result a forced draft canV be used, but I prefer to have the various passages and ports so proportioned that a pressure of gases can always be mamtW'een theradiatin Vchamber and working chamber are opene The essential feature chamber beof suiicient size to permit substantially complete combustion ofjthe gases lgenerated by the normal operation of the grate, and 'that the passages 1n usey gradually ldecrease in size as the gases the point ofjinal combustion, in order to ma'itnain the pressure while the volume of the. gases decreases.

By vsubstantially complete combustion I mean that substantiall all of the oxygen and carbon present shall a've been combined toas great an extent as may be possible with the mixture of these two substances that is used and the temperature that may be cre'- ated, so that there will be only a small amount of combustion that will take place in the working chamber.

The particular embodiment ofmy inVen-u ltion which isgiven as an example of one of the many ways in which my invention l may be used relates to furnaces for annealing and the like, having a carriage ada ted to carry thematerial to be treated, w ich can be wheeled into and out of the furnace are iiues for the distribution of. heat. "By my. present invention I am able to make such a furnace of great efficiency.

In constructing this particular type of 'furnace I use a furnace shell having an apl'propriate chimney iue, and adapted to receive a carriage on which the materials to be treated may be placed and by means of which heat may be distributed 1n the furnace. The grate or other place for initial combustion may be either made'integral with 1 the shell of the lfurnace or. preferably be made movable in the manner hereinafter described. The furnace shell may either .be made .to open at one end with an ordinary door, or

' warming and in the other of which the matetained -which will drive the heat into the radiating chamber as soon as the ports bev and lead them to the preliminary heating of such proportioning is that the main heat advance from chamber,l and in the oor of which carriage it may preferably be made with doors at both ends, and extensions beyond the doors, in one of which the carriage and4 materials to be treated may be given a preliminary rials which have been treated may be allowed -toI cool slowly. i' The carriage is providedl with an internal chamber of a volume sufficient to vallow practical completion .of combustion, and connected with this internal chamberis a ,heat distributing chamber which should be covered by 4partition sufiiciently. thin tol allow heat to radiate through to thematerial which .is being. carried byV the carriage. Flues to permit the direct flow of heat from the body of the carriage to the material 4to be treated are positioned at various points around the edges of the carriage, and are connectedby 'appropriate ports with the heatl distributing chamber. I also find es 1t 1s advantageous under somecircumstances to take the Waste gasesthat have passed throu'gh the carriage in the furnace .proper chamber and allow them to ass through an- 96 4other similarcarriageon w ich Woik Wait-v 'and Fig. 3 is 'a section on line III- III of Fig. 2, looking 1n the directiondesignated by the arrows shown in Fig. 2.

In these drawings the numeral 2v repre- Vsents the permanent portion of the furnace or shell, vwhichl comprises a heating portieri 3 and a warming portion 4.. Within this, shellare tracks. 5, on which run'the car- 105 riages 6.v In the body 'of each of the carriage's'6 is a main combustion chamber 7, in'to which -unconsumed gases may pass lthrough the passage 8. Connected with the main combustion chamber 7l yis the heat dis- 11o tributing chamber 9, which lis separated from the main combustion chamber 7 by the baffle walls 10. Leading from the heat distributing chamber 9 are f orts 1l, which i open into 'ues'12. The ues 12 are con- -115 trolledby dampers 13, which may be adju'sted from the outside of the carriage 6'.v f

The egressof the consumed gases is pro videdA for by the flues 14, which are positioned across the end of the carriage at the same end as the passage 8. The ues 1 4: open downwardly intojthey passage 15. The

,ends of the passage 15 are adapted to register with passages 16 in the permanent shelly 2. i Leading upwardly from the passages 16 are flues 17, which conduct the waste gases .to the return flue 18 which extends through the roof of the heating portion 3 of the permanent shell 2. From the return flue 18 the, gases may be allowed to 130 pass in any convenient Way tothe stack nary construction,

preferably be s o constructed that be opened tol ali-ow a truck 6 but I prefer to utilize them for warming a second'charge of material in the hot gases are allowed to pass from the return flue 18 by port 19 to the passage 20. In passage 20 the gases flow down to pas. sage 2l and through passage 21 to passage 8 in the secohd carriage 6 inthe warming.

or fire chamber. While this fire chamber may be made integral with the furnace shellit movable on tracks 24. 23 is a grate 25, of ordi` at the rear end of which is a bridge wall 26. Through the bridge `Wall 26'runs a"passage 27, for the admission of air, in additionto that which passes through the grate 25. In order that a tight joint mayreadily be made between vthe grate portion 23 and the passage 8, through which 2, I prefer to have ithin the member thegases are admitted to the truck 6, the- 23 is provided with an extenis adapted to lit into the opening of the passage Y f In addition to the permanent furnace o1" permanent4 extensions thereof may f grate portion sionv 27, which 8, as shown in Fig. 3.

shell 2', be provided, as indicated by the numerals 29 and 30. The extension29 may conven iently be used as a cooling chamber for the extension 30 may-be used 'as a chamber for the Aintroduction riages bearing the goods.

preliminary of the Car gates 31. The warming portion is provided with gates 32. The extension 29 is provided with gates 33, and the extension'305is pro videdA with gates 34. These gates ishould they may to pass from one portion of the furnace to the next Withoutl admitting outside air.

In operation a4 truclr6, bearing material lto be treated, whichmay be either open or covered, depending on the requirements 'of tlA y, "lark,l is brought into the heating porf the shell 2. At the same time a second truck 6, likewise bearing material .to'beftreated, is brought into the Warming portion 4 of theshell 2.

the manner ,A shown 1n Figs. 1 and 2. To accomplish this represents that portion of the furnace in which is positioned the grate The variousI por'-v -"an additional carriage 6' is tions of the furnace are preferably equipped For example, the heat-l pout departin The grate'm'em-q ber 23--is thenmoved `forward until the ex-l tension 28 enters the outer end of the passage 8 and this joint is scaled with clay.. At

between the the connec- Incompletely burned gases from thegr'atel 25 flow through the passage 8 into the main combustion chamber 7, together with addi-` tional air,

bridge 26 by gases are substantially,v consumed in the combustion chamber 7 with the generation offa great amount Of heat which is trans- Initted to the heat distributing chamber 9.

which is passed through the This heat causes the walls of the heat distributing chamber 9. and the baille walls 10 to become incandescent and the amount of heatvwhich isl thereby absorbed insures an abundant amount of heat being present as a reserve, so that an even temperature may be maintained throughout the material which is being treated. In addition to the heat which is tranmitted to the material to be treated through the roof of th'e covered chamber 7, and the heat distributing chamber 9,'l heat is 'transmitted directly7 through the flues l2. After the consumed gases have passed completely around' the material to be treated they How f1-through the various passages indicated into vthhefsecond truck 6, which is positioned in ythe warming chamber, l:tcfagconsiderable degree. After one batch 'fof-'material hasbeen treated the carriage 6 which was in' the heating materials which have been heated, and the"y v and serve to warm it chamber 3 is if is moved into the heating chamber, and i y moved into the Warming chamber 30whereupon the operation is repeated. y' n i The gates 31 and 32 are closed,

means of the passage 27. These 4 mmofved.' on intothe extension 29, the cariage6 which was inthe warming chamber Owing tothe great amount of heat which I has been absorbed by the truck 6, additional vheating'of the extension 33 to prevent too rapid cooling of the material is ordinarily unnecessary, Iand it will usually be lfound sufficient if thetruck 6 is allowedto 'cool normally. y

tgis'apparent that many changes may be Amade iiil the 'details v.of 'such a furnace withfromthe spirit of my inven tion, since W ajt VI claim is:

1. Inv av furnace, a working chamber, ,/a place for initial combustion, a heat reservoir having an extended surface for the absorp tion of heat, adapted to distribute,heat to the .working chamber both directly' and by iii;

radiation, said heat reservoir comprising a place for initial combustion of fuel, a heat ber, a plurality can continue anda heat-distributing chainof lil-ues connecting such chamber and said work#A ing chamber, yand.means for controlling lthe,l

heat-distributing ases through said flues.l`

passage of v urnace, a working chamber,1a

2. Ina

reservoir comprising a mainl heat chamber and a secondary heat chamber adapted to transmit heat to the working chamberA by radiation, a plurality of flues leading fromr,I the secondary heat chamber to the workingv chamber the arrangement of the heat reser- 4voir and iues being such that the heated gases must pass in proximity to the working chamber for substantially'the length of such chamber before entering suchv .cham- 4 ber throughsaid ues.

.. transmit heat to the workinggchamber byv radiation, a plurality of lues leading .from y vthe secondary heat chamber to the working 4 so con- 3. -In a furnace, a working chamber, a place for initial combustion of fuel, a heat reservoir comprising a main heat chamber and a secondary heat 'chamber adapted to chamber, said heat reservoir bein structedas to supply an extende surface for the absorption of heat and to lengthen the flow of substantially all of the hot gases so that they may heat suchextended lsurface-before passing throughV said lines.

4. In a furnace, a working chamber, va place for initial combustion, a heat reservoirl comprisingA a primary heat chamber in which combustion can be. continued and'.

a secondary heat chamber inroximity to said workingvchamber, adapte to transmit heat from saidimain heat chamber and distributeit in the Working chamber both -directly and by radiation, and -having an extended surfaceto hold heat until absorbed in the working chamber, a plurality of lues leadin from said secondary heat chamber` to sai working chamber, and means for Witnesses:

:controlling they passage of gases through said ilues.

5. In a" furnace, a working chamber, a place for initial combustion, a'heat reservoir comprising a primary combustion chamber and a heat-distributing chamber, so arran ed asto supply extended surfaces for the a sorption of heat, and an extended passage for gases within which combustion can be substantially completed, .said heat reservoir being adapted to give an even distribution of heat to 4the working chamber l both. directly and by radiation.

'6a-.In la furnace, Dthe combination of a shell, a place for initial combustion, a truck adapted tol-move 1n saidV shell and to carry.

material to'be-treated, Va chamber in said truck adaptedl to receive unconsumed. gases from said place for initial combustion, said chambers to the other, a combustiony chamher in each of lsaid trucks, a place forl initial combustion adapted toI supply unconsumed gases to one of said ,combustion chambers, and means whereby the heat generated in lsaid combustion chamber may be utilized to warm theother truck.

vIn witness whereof I'have hereunto set my hand in the presence of two witnesses.

ALFRED sMALLwooD.

ARTHUR I-I.' BRowN, I CHAnLns R. Riom'.

chamber having .an extended surface 

